The latter. With quality register allocation, the same register can be used for multiple variables (or unnamed intermediate results) within the span of a few in

The latter. With quality register allocation, the same register can be used for multiple variables (or unnamed intermediate results) within the span of a few instructions. The inverse is also true: the same variable could find its value in multiple registers. DWARF appears to support mapping symbol locations to registers, but I’ve never seen a language environment/debugger that takes advantage of it for optimized binaries.